EDEMO EDEMO CMMG Inc 22LR AR Conversion Kit Mk57 w/ 3 Magazines 10rd Black 546A6B9-10RD EDEMO13 EDEMO1. 7x28mm Upper Receiver Group into a .22LR in seconds The new Mk57 .22LR Conversion Kit is simple to use. Just remove the existing CMMG bolt carrier...